I don’t see why. In cruise you are separated from VFR levels, so no conflict. That means you are only going to conflict with VFR in climb or descent, so you just stop/slow climb or descent until you are visually clear. That wouldn’t conflict with your clearance, so no talking to Air Traffic required.
If you want to stop your climb or descent you will need a clearance and you need to sort it out with the VFR traffic.